GRAP 4 curbs invoked in Delhi-NCR amid sharp dip in air quality

Unfavourable meteorological conditions, combined with vehicle emissions, paddy-straw burning, firecrackers, and other local pollution sources, lead to hazardous air quality levels in Delhi-NCR during winters.

The Centre’s panel on Delhi-NCR’s air quality on Wednesday invoked curbs under stage 4 of the Graded Response Action Plan (GRAP) amid a sharp dip in air quality due to unfavourable meteorological conditions, according to an official order.

Calm winds, low temperatures, and foggy conditions allowed the accumulation of pollutants in the region, with the air quality index soaring from 275 on Tuesday to 396 at 6 pm on Wednesday. The India Meteorological Department and the Indian Institute of Tropical Meteorology predicted that AQI may breach the 400 mark soon.

Accordingly, the Commission for Air Quality Management (CAQM) directed authorities in Delhi-NCR to "straightaway invoke" all actions under stages 3 and 4 with immediate effect. Stage 4 curbs include a ban on all construction activities, entry of non-essential polluting trucks into Delhi, and mandatory shifting of school classes, except for classes 10 and 12, to hybrid mode. Non-essential diesel trucks are prohibited from entering Delhi, while Delhi-registered BS-IV and older diesel-run heavy goods vehicles are banned, except for essential services under Stage 4.

During winters, the Delhi-NCR region enforces restrictions under GRAP, which categorizes air quality into four stages – Stage 1 (Poor, AQI 201-300), Stage 2 (Very Poor, AQI 301-400), Stage 3 (Severe, AQI 401-450), and Stage 4 (Severe Plus, AQI above 450). Unfavourable meteorological conditions, combined with vehicle emissions, paddy-straw burning, firecrackers, and other local pollution sources, lead to hazardous air quality levels in Delhi-NCR during winters.